The quality of the maternal and developmental environments have been demonstrated to impact a number of traits in adult humans and other animals, including likelihood of developing coronary heart disease, type 2 diabetes mellitus, and hypertension;performance in learning and memory tasks;stress reactivity and immune responses. Two competing hypotheses have been proposed to explain how a mismatch between the quality of the developmental environment and the quality of the adult environment should impact the health and fitness of adults. The environmental matching hypothesis proposes that individual fitness is maximized when the quality of the developmental and adult environments are similar. The second hypothesis, the silver spoon effect, instead proposes that individuals from high quality developmental environments always have higher fitness than individuals from low quality developmental environments, regardless of the quality of the adult environment. The proposed research will test these hypotheses simultaneously by experimentally manipulating exposure to bacterial antigens and stress hormones in females, developing young, and adults. This research will be conducted with zebra finches (Taeniopygia guttata). By manipulating the quality of both the maternal and developmental environments, this research will also address the ability of mothers to ameliorate the negative effects of a poor quality developmental environment for young. The use of a songbird as a research animal will provide an opportunity to test the effects of a mismatch between the developmental and adult environments on vocal learning processes. Finally manipulation of exposure to both endotoxin and corticosterone will isolate the effects of exposure to an inflammatory stimulus and associated activation of the hypothalamic-pituitary-adrenal (HPA) axis from the effects of elevated glucocorticoid levels alone. These studies should provide insight into the developmental origins of adult diseases and variation in behavioral responses. Research into the effects of mismatches between the developmental and adult environments can provide predictive information about the children most at risk from a low quality maternal or developmental environment and the most likely impacts on physiology and behavior. PUBLIC HEALTH RELEVANCE: We will test the ability of the maternal and developmental environments to adaptively prepare young for likely conditions in the adult environment. These studies should provide insight into the developmental origins of adult diseases and variation in behavioral responses. Research into the effects of mismatches between the developmental and adult environments can provide predictive information about the children most at risk from a low quality maternal or developmental environment and the most likely impacts on physiology and behavior.